car sometimes just doesnt start and sometimes stalls at stop

[kevmss 1]

Hi I just got a 06 fortwo diesel from and old guy I know, he just wanted to sell it because he had lots of money into it already and it still had a problem. He told me Everything is good only sometimes it stalls at a red light or stop sign, and also sometimes it doesn't start after that. Then when he waited for 10 mins it started perfectly again. It hasn't stalled since I got it but twice right after driving I shut the car off and then it would not start. It cranks and cranks but just doesn't start. Then after I waited a few mins it started back up. He brought it to Mercedes and a few grand later the problem was still there. The replace the fuel pump, the fuel filter, also the battery and maybe some more stuff but nothing changed anything. Does anyone have any idea what this could be or experienced something similar with their car? I thought of the egr could that be a problem if it is pluged up? 

[tolsen 630]

Check if terminal at SAM fuse box powering electric feed pump is burnt.  Common fault on these cars.  Best to add external relay.

[kevmss 1]

I'll check that when I get home, but why would it start good sometimes?

Also I forgot to say there is an engine code p0401 

 

[kevmss 1]

7 hours ago, cadillacman said:

 

The FuelPump pin, N11-3-10, is making poor-sometimes-bad contact ... hit and miss

Try kicking the SAM when it won't start

 

p0401 = you have a clogged up EGR valve

 

but REALLY ... just joking ... do NOT kick your SAM

You could try wiggling plug N11-3 on the SAM, or unplugging and reseating it

If it starts after that ... good indicator it is N11-3-10 pin

Thanks for the reply. I tried this wiggling the wires and fuse, they all look clean too.

While I was driving this time the engine shut off and I had an obd scanner connected so I checked it and a code came that I didn't see before p0336 crankshaft positioning sensor "A" circuit range/preformance. Once I cleared it the car started again, but the second time it didn't start after I cleared it, but when I waited it started again. 

Any help is appreciated. 

[tolsen 630]

Seems engine started once crank position sensor had cooler down.  Takes only a minute or two to replace provided you got the skills.

[kevmss 1]

4 minutes ago, tolsen said:

Seems engine started once crank position sensor had cooler down.  Takes only a minute or two to replace provided you got the skills.

The skills I believe I should have(have done a lot of work on 3 audis I've owned which are not always simple) don't know too much about smarts though... I'm guessing it would be accessible from the bottom?

[tolsen 630]

Study below thread.

 

[kevmss 1]

I ordered a sensor from ebay should get it on the 25th I'll see how it goes. Thanks again

[CANMAN 23]

20 hours ago, tolsen said:

Seems engine started once crank position sensor had cooler down.  Takes only a minute or two to replace provided you got the skills.

Tolsen, 

I think you just got back from the pub when you wrote that.

Changing the Crank Position sensor is the second hardest job on a smart, the only thing worse is changing the starter.

canman

[tolsen 630]

The problem is owners do not maintain there cars no more.  I remove my crank sensor periodically to give it a good clean and lube its screw and bore where it sits.  My personal best removal time is seven minutes.

[Nigel 287]

I suspect Tolsen did one like yours a long time ago and since then has made it a point in his preventative maintenance schedule.

[tolsen 630]

1 hour ago, GRP151 said:

Please share with us the steps involved after the car is jacked up and the rear panel  and fenders are removed.

What do you do next?

Or is your sensor hole so clean that you only have to reach in, unclip the connector and loosen the securing bolt and lift it out? l wish l knew why the frigen thing was impossible to pull out by twisting and pulling it that it broke! You would think plastic and aluminum would be somewhat compatible restricting the swelling of either materials!

 

I remove sensor from above.  Unclip connector to oil pressure sensor since on same wiring harness branch as engine speed sensor.  Then unscew engine speed sensor T30 screw from above having first unplugged rail pressure regulator connector and removed rubber elbow between EGR valve and inlet manifold.  I lift out engine speed sensor by pulling on its cable.  Easy if its bore is clean and greased.

 

Greased aluminium does not corrode but aluminium exposed to salty water does in which case the removal procedure can take a day or two and nothing but swarf will remain of sensor.

 

 

[tolsen 630]

Turbo?  Surely you must mean intercooler!

 

You must be smart to replace engine speed sensor.

[LooseLugNuts 557]

hope he's spraying penetrating oil on it everyday until the part comes in

 

if Tolsen says it can be done with turbo on id go ahead and try it his way...

 

 

some people have the knack ..

[kevmss 1]

I got my sensor today installed it and the car works great again.

[MikeT 744]

On 10/18/2016 at 2:16 PM, cadillacman said:

 

The FuelPump pin, N11-3-10, is making poor-sometimes-bad contact ... hit and miss

Try kicking the SAM when it won't start

 

but REALLY ... just joking ... do NOT kick your SAM

 

Funny you mention this.  We have an external relay on the fuel pump circuit and in Portland OR last Thursday on the way back home from Desert Trip the car turned over without firing.  I had a T-10 in the car but decided to give a quick boot to the (new two and a half years ago) SAM... and it started first try.  I think I need to replace the female contact for the fuel pump (the low beam female connectors were done when I did the headlights last spring).

[kevmss 1]

56 minutes ago, GRP151 said:

 

Was it difficult to remove?

How long did it take you?

I took it out last Wednesday already when I ordered the sensor, it took me around an hour to take out,but I also took out the EGR valve and cleaned it abit. Today it took me probably 30 minutes to put in new one and assemble

[kevmss 1]

Just now, kevmss said:

I took it out last Wednesday already when I ordered the sensor, it took me around an hour to take out,but I also took out the EGR valve and cleaned it abit. Today it took me probably 30 minutes to put in new one and assemble

It wasn't too hard it just takes a long time to get screws/parts out in such a tight spot

[kevmss 1]

Wasn't stuck, it came out half way by pulling the cable an th rest I pryed out really easily

[Thegorillabear 16]

I am having a similar problem but I'm not sure if I am reading this correctly.  05 Cdn CDI runs fine does highway speed.  I get off the highway on to a major street and as I slow down the engine stalls, the instrument cluster lights up like a christmas tree and it will not turn over.  I try everything (pop into and out of gear, try a 1 person bump start, cycle the lock in case it's the anti theft system) but no luck.  About 10 min later once everything has been let sit, it turns over andfires right up.  Do you guys think the crank sensor going could cause this or is it something more involved?

 

[LooseLugNuts 557]

42 minutes ago, Thegorillabear said:

I am having a similar problem but I'm not sure if I am reading this correctly.  05 Cdn CDI runs fine does highway speed.  I get off the highway on to a major street and as I slow down the engine stalls, the instrument cluster lights up like a christmas tree and it will not turn over.  I try everything (pop into and out of gear, try a 1 person bump start, cycle the lock in case it's the anti theft system) but no luck.  About 10 min later once everything has been let sit, it turns over andfires right up.  Do you guys think the crank sensor going could cause this or is it something more involved?

 

 

that would be my guess

 

ive seen it happen on many other makes...usually when they start up after cooling off its the crank sensor...(sometimes the coil if there is only one for all cylinders)

 

but since theres no coil on these id be aiming my troubleshooting towards the crank sensor ...if that checked out fine id head over to the fuel pump

 

the odd part is where you say it wont turn over...

Edited November 12, 2018 by LooseLugNuts

[Thegorillabear 16]

If it stalled then started after a few min but cranked the fuel system would have been my first guess.  But when I turn the key everything on the dash comes to, the glow plugs cycle but the starter just does not engage.  That is why I was wondering if it was the cranksensor.

 

[Willys 747]

Check all your ground attachment points.....don't just look at them, take them all off one by one including the battery, ( but run a jumper from battery to car when you do or your radio will go into safe mode and if you do not have code you will need it hacking, ask me how I know) You'll find them to look perfect but some don't conduct! I simply wired brushed them all and added a smeer of dilectric grease to stop it again from happening. Just a suggestion.

 

[Thegorillabear 16]

Thanks. I'll give the grounds a go and see how that works out.  I excluded that because everything (lights, radio, blower fan, locks) seemed to be working just fine.

[LooseLugNuts 557]

you can rule out the fuel pump and crank sensor then

 

they dont have anything to do with a no crank situation